1. Open your SSH session.
2. Login.
3. Click File, Reconnect.
4. TeSSH will disconnect, reconnect, AND bring up the Disconnect / Reconnect / Offline dialog.
5. If you click Reconnect, you go back to step 4.
6. Repeat until you get bored, or click Offline, whereupon you are still connected and everything is fine.

Note that after some time doing various things between step 2 and step 3, you may not be able to reproduce this issue and it all works perfectly.